| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a catalyst for cleaning an exhaust gas which increases the amount of HC components adsorbed without thickening a catalyst layer and can sufficiently remove the desorbed HC components. <P>SOLUTION: The catalyst for cleaning the exhaust gas 3 which is arranged in the exhaust gas passage of an engine is provided with a honeycomb carrier and the catalyst layer 6 formed on the surface of the cell wall 5 of the honeycomb carrier. The catalyst layer 6 is laminated with at least two of HC adsorbing layers 11, 13 containing a HC adsorbing material and cleaning layers 12, 14 containing noble metals for a catalyst. The HC adsorbing layers 11, 13 exist in the cell wall 5 side nearer than the cleaning layers 12, 14. When the side close to the inflow part of the exhaust gas is defined as an upstream side, and a side close to the outflow part is defined as a downstream side, the HC adsorbing layer 11 of the upstream side is thicker than the HC adsorbing layer 13 of the downstream side and the cleaning layer 14 of the downstream side is thicker than the cleaning layer 12 of the upstream side. <P>COPYRIGHT: (C)2009,JPO&INPIT |
